Power Plants in Massachusetts

Massachusetts's power sector in numbers

Bywatts maps 125 operating power plants with 9.3 GW of nameplate capacity in Massachusetts. Natural Gas leads with 58% of that capacity across 22 plants, followed by Hydro (19%) and Oil (17%). The inventory also includes 33 plants (6.1 GW) that EIA-860 lists as retired and 2 partly retired with no operable units of their recorded fuel; the largest retired plant is MYSTIC GENERATING STATION (2,376 MW, retired 2024).

The largest operating plants are CANAL (1,165 MW, Oil, NRG CANAL LLC), NORTHFIELD MOUNTAIN (940 MW, Hydro, FIRSTLIGHT POWER RESOURCES, INC. - MA) and FORE RIVER GENERATING STATION (872 MW, Natural Gas, CONSTELLATION MYSTIC POWER LLC).

Of the 122 operating plants with a recorded commissioning year, 58 came online in 2000 or later and 46 in 2010 or later; the busiest decade for new capacity was the 2000s (2.6 GW).

The largest operators by operating capacity are NRG CANAL LLC (3 plants, 1.2 GW), FIRSTLIGHT POWER RESOURCES, INC. - MA (4 plants, 1.0 GW) and CONSTELLATION MYSTIC POWER LLC (1 plant, 872 MW).

Retail electricity sales in Massachusetts reached 51.7 TWh in 2025, down 5.3% over ten years and up 4.7% year on year; residential customers took 40.3% of it. The average retail price across all sectors was 25.56 cents per kWh, up 51.2% since 2015.

The database also maps 7 named substations (3 of the 5 with a recorded voltage are rated 345 kV or above), 4 data centers (operators include CoreSite, Equinix and Lumen Technologies), 245 solar installers and 97 solar companies in Massachusetts.

Operating capacity by fuel

Retail electricity sales

Sources: HIFLD power-plant inventory (capacity, fuel, operator), EIA-860 (commissioning year, retirements, operable capacity), EIA retail sales and revenue series through January 2026. Counts are of plants Bywatts lists, not every generator in the state.